Fix #0017605: Regression issue with upgrade step 184

Background and comments / rational on this commit are in http://www.mantisbt.org/bugs/view.php?id=17605.
This change should really have been done as a separate patch and PR.

db_fetch_array() returns indexed named varaibles - i.e. rest of code base uses $t_row['id'] etc.

Personally, I'm not sure whether this code will have ever worked from the day it was coded.